This invention concerns an underpressure-activated valve device for a drinking receptacle. The valve includes a valve head, a valve seat and a flexible membrane. The valve seat is in force-transmitting connection with the flexible membrane, whereas the valve head is fixed to an associated support structure. Particularly, the invention is directed towards a valve design suitable for mould casting and mass production.
The patent literature discloses several devices that utilize underpressure for activating a valve for a drinking receptacle, for example as shown in U.S. Pat. No. 6,290,090 and in Norwegian patent no. 315182. Common to prior art in this area is that the valve seat is fixed to an associated structure, and that only the sealing surface of the valve head can be moved or change shape during activation of the valve. By making the valve seat moveable, however, it is possible to obviate the need for the valve head requiring horizontal sealing surfaces that must be pulled out of the casting mould after moulding, which may inflict damage to such a sealing surface. The sealing surface may also become damaged during assembly, inasmuch as it becomes strongly deformed when forced through a valve opening. Having to inspect the sealing surface by means of known inspection methods provides both an increase in cost and complexity.